Ghost cities of China: Identifying urban vacancy through social media data

“Ghost Cities” have become a phenomenon of global interest since 2009 when popular media highlighted the existence of Ordos, a large Chinese city that was almost entirely vacant. The term is used to describe housing vacancy associated with overdevelopment and can refer to small communities, neighborhoods, or even whole cities that lie vacant. Ghost Cities are particularly prevalent in China where housing vacancy has become a serious concern for many second and third-tier cities. Measuring the extent of these vacant areas has been challenging due to Chinese data restrictions. This research tests whether it is possible to collect data, scraped from Chinese social media open access API's including Dianping (Chinese Yelp), Amap (Chinese MapQuest), Fang (Chinese Zillow), and Baidu (Chinese Google Maps) to develop a computational model to identify areas considered to be Ghost Cities. The model created for this study is based on the idea that thriving communities need access to basic amenities. Therefore Hansen's gravitational model was applied to give an “amenities score” for residential locations based on their accessibility to restaurants, banks, grocery stores, beauty salons, KTV, medical facilities, schools, and malls Moran's I spatial autocorrelation was applied to the amenity scores below the mean to determine spatially clustered residential locations with low scores. The results were considered potential Ghost Cities and were visited in Chengdu and Shenyang to confirm the accuracy of the model. These site visits showed that the model identified transitional, underperforming, or vacant housing in these cities, illustrating that it is possible to use data scraped from social media to identify underused residential developments.     

Everyday life patterns and social segregation of expatriate women in globalizing Asian cities: cases of Shanghai and Seoul

Shanghai’s ‘planned’ and Seoul’s ‘evolved’ expatriate communities represent contrasting approaches to housing the highly skilled professionals and their families. The study shows how the two distinctive environments produce different spatial patterns in everyday life, and also how they affect the social segregation of the expatriate women in the two cities. Shanghai’s gated compound entails an introverted, self-contained lifestyle with little contact with the local people. Seoul’s naturally evolved community is integrated with local neighborhoods leading to the wider range of daily destinations and more everyday contact with local people. Although the inter-expat social relations appear stronger within Shanghai’s walled residential areas, the daily interaction with host city locals is more pronounced in Seoul’s mixed foreign quarters. The study suggests that, among expats and locals, residential form which allows small-scale, everyday routine social interactions may be more conducive to building a sense of community in increasingly globalizing Asian urban centers.     

Contemporary tendencies in Colombian urban planning: the case of the ‘Planes Parciales’ in Medellín

After decades of internal conflict, Colombia is experiencing economic growth and urbanization. It remains, however, one of the most socially unequal countries in Latin America. Medellín, acclaimed the most innovative city, implemented large-scale transport infrastructures to link socially excluded areas to the city; new educational and cultural facilities; new public spaces and housing projects, rooted in the Barcelona model. This so-called ‘social urbanism’ has shifted local perceptions, though its socio-economic impact has been questioned. This paper focuses on the less analysed transformations in planning policy and management through two instruments: the Land Use Plan (Plan de Ordenamiento Territorial – POT) and the ‘Plan Parcial’. The research, based on a desktop review, interviews and site visits, examines the application of these instruments in Medellín, reflecting on how they contribute to achieving the aims of ‘social urbanism’. The paper explores the differences between ‘rhetoric’ and practice that are reflected in those between the city’s overarching plan (POT) and the implementation of ‘planes parciales’, focusing on redevelopment, urban renewal and urban expansion. Such differences mirror the deficiencies in the adaptation of the ‘urban project’ Barcelona model in Medellín, and provide the basis for a call to develop ‘social urbanism’ that is genuinely more socially, territorially comprehensive and inclusive.     

Same Neighbourhood … Different Views? A Confrontation of Internal and External Neighbourhood Reputations

Residents and non-residents are likely to think differently about a neighbourhood's reputation. Relatively little is known about the similarities and differences between these internal and external types of neighbourhood reputation or the relationship between reputations and ‘real’ or ‘objective’ neighbourhood characteristics. This paper addresses two points: first, the extent to which neighbourhood reputations differ between and within groups; second, the extent to which these neighbourhood reputations are associated with measured neighbourhood characteristics. Data from a specially designed survey carried out in 24 neighbourhoods in Utrecht, the fourth largest city in the Netherlands, are used. Analysis of the data showed that neighbourhood reputations are rated higher by residents and estate agents than by other city residents. Within the group of other city residents, differences were found in how neighbourhood reputations are rated by socio-economic status, ethnicity and educational background. Further, it was found that neighbourhood reputations are correlated with measured social characteristics of the neighbourhood, while physical and functional neighbourhood characteristics are of less importance.     

“GOOD” NEIGHBORHOODS IN PORTLAND,OREGON: FOCUS ON BOTH SOCIAL AND PHYSICAL ENVIRONMENTS

ABSTRACT: We conduct an empirical investigation of the social environment of “good” neighborhoods in physical form in a model of the “compact city,” Portland, Oregon and discuss the implications for design and evaluation of policies inspired by smart growth and new urbanist movements that focus on the urban form and transportation dimensions of neighborhoods, and of housing assistance policies designed to change the economic mix in neighborhoods. We conceptualize the physical and social dimensions of the “good” neighborhood environment and develop an approach to operationalization that uses publicly available data. Our findings indicate that for the most part, Portland has been successful in creating neighborhoods at several economic scales that feature not only the connectivity, accessibility, mixed land use, and access to public transit that characterize “good” neighborhoods from a physical perspective, but also a “good” social environment indicative of strong ties and collective efficacy. However, there are signs that in the process, Portland may be creating poverty areas that lack connectivity, accessibility, and access to public transit and a mix of destinations.     

ENTREPRENEURSHIP IN THE NEIGHBORHOOD: SHIFTING PATTERNS OF ECONOMIC ACTIVITIES IN RESIDENTIAL NEIGHBORHOODS IN FIVE DUTCH CITIES

Cities are oftentimes seen as undergoing a process of “emergence” in the “new economy.” However, this process has largely remained empirically underdetermined. This article examines the intra‐city geography of emerging businesses in newly dominant sectors of the urban economy. The change in dominant sectors coincides with a shift towards small‐ and medium‐sized businesses, creating new economic opportunities for urban residential areas. The residential neighborhood is introduced as a place where supply and demand side drivers operate to attract or limit such new economic activity. Allen Scott's perspective of the cognitive‐cultural economy is used to analyze which neighborhoods are flourishing sites of the cognitive‐cultural sectors. His perspective on industries that are on the rise in urban environments and their growth potential proves very valuable. Social demographic characteristics on the level of the neighborhood are used as predictors of the composition of the local economy. The analyses show that in particular wealthy, gentrified neighborhoods are more prone than others to becoming “hubs” of the cognitive‐cultural economy. However, disadvantaged neighborhoods may under certain conditions serve as incubators for business start‐ups as they offer low‐rent office spaces. This has important consequences for their future economic growth potential as well as the distribution of successful businesses in the city.     

Toward a Theory of Gentrification A Back to the City Movement by Capital,not People

Consumer sovereignty hypotheses dominate explanations of gentrification but data on the number of suburbanites returning to the city casts doubt on this hypothesis. In fact, gentrification is an expected product of the relatively unhampered operation of the land and housing markets. The economic depreciation of capital invested in nineteenth century inner-city neighborhoods and the simultaneous rise in potential ground rent levels produces the possibility of profitable redevelopment. Although the very apparent social characteristics of deteriorated neighborhoods would discourage redevelopment, the hidden economic characteristics may well be favorable. Whether gentrification is a fundamental restructuring of urban space depends not on where new inhabitants come from but on how much productive capital returns to the area from the suburbs.     

Amsterdam in the 21st century: Geography,housing, spatial development and politics

This city profile provides a multi-dimensional overview on the most recent social, economic, political and spatial changes in the city of Amsterdam. We map the social-geography of the city, discussing recent housing and spatial development policies as well as city-regional political dynamics. Today, the city of Amsterdam is more diverse than ever, both ethnically and socially. The social geography of Amsterdam shows a growing core–periphery divide that underlines important economic and cultural asymmetries. The tradition of public subsidies and regulated housing currently allows for state-led gentrification within inner city neighborhoods. Public support for homeownership is changing the balance between social, middle and high-end housing segments. Changes in the tradition of large-scale interventions and strong public planning are likewise occurring. In times of austerity, current projects focus on small-scale and piecemeal interventions particularly oriented to stimulate entrepreneurialism in selected urban areas and often relate to creative economies and sustainable development. Finally, underlying these trends is a new political landscape composed of upcoming liberal and progressive parties, which together challenge the political equilibriums in the city region     

Building an urban ‘renaissance’: fragmented services and the production of inequality in Greater Downtown Detroit

Downtown Detroit has been undergoing a renaissance in recent years which is in stark contrast to the economic and social situation in much of the rest of the city. This renaissance has been taking place despite the city’s ability to provide good municipal services such as streetlights, security, public space and transport. This article focuses on how four areas which constitute part of Greater Downtown Detroit have relied on different combinations of actors to create and provide the services and amenities deemed necessary for capital investment and middle-class consumption. Each area has its own initiatives and actors who implement them, further fragmenting the city between its core and periphery. Renewed public spaces, private police forces and resident initiatives in middle-class neighborhoods have been created to serve specific needs of the small areas they serve. Rather than being unique, Detroit is an extreme example of fragmented and polarized urbanism which is part and parcel of contemporary cities. We argue that rather than passively reflecting existing socio-spatial divides, these private initiatives in Greater Downtown Detroit actively contribute to the production of sociospatial inequalities across the city.     

Neo–Bohemia: Art and Neighborhood Redevelopment in Chicago

Drawing on an extended case study of Chicago’s Wicker Park neighborhood, this article develops the concept of neo–bohemia. Neo–bohemia suggests that traditions of cultural innovation in older city neighborhoods persist, but that these bohemian traditions intersect with economic development in new ways in the post–Fordist city. Neo–bohemia supports both residential gentrification and the concentration of entertainment and new media enterprises, creating the context for the redevelopment of former industrial spaces in Chicago. Neo–bohemia complicates contemporary urban theories that stress deconcentration, and theories of urban tourism that overstate the regulated and hermetic nature of consumption spaces.     

THE ROLE OF MUNICIPAL‐LEVEL FACTORS IN NEIGHBORHOOD ECONOMIC CHANGE

Despite extensive studies on neighborhood change, the role of municipal‐level factors in neighborhood economic change has been underexplored. This article reviews diverse social science literature and makes theoretical connections between city size and homogeneity of city population and municipal performance, which is accordingly associated with neighborhood economic health. Building on the insights from the literature, this study hypothesizes that neighborhoods stay economically healthier in smaller cities and more homogeneous cities. This study presents a multilevel analysis of neighborhood economic change in 35 U.S. metropolitan areas between 1990 and 2000 and finds empirical evidence to support the proposed hypothesis.     

Re-sensing Las Vegas: aesthetic entrepreneurship and local urban culture

Cities are dense, sensory environments that provide various stimuli that require interpretation and representation. The embodied sensuous lived experience of urban life, however, is much more dynamic and fluid than any one representation can encompass. A conflict often emerges between the dominant image of a city and what actually happens in it. As such, this creates a tension about a city’s ‘sense of place.’ I employ the notion of ‘aesthetic entrepreneurship’ to designate the practices of certain individuals who seek to create new senses of place in the face of opposition or in times of social crisis. I explore the ways aesthetic entrepreneurs have used sensory knowledge to create alternative narratives and images of Las Vegas after the economic crash of 2008. Each of the aesthetic entrepreneurs discussed here has actively sought to develop a new sense of place for a city popularly defined by its dominant neon imagery.     

One city's ‘urban cosmography’

Illustrations of urban scenes naturally describe the physical characteristics of the places depicted. These representations also express implicitly broader beliefs which tie the spatial order of the surrounding world to local systems, institutions, and human actions. Images of a city embody, therefore, an ‘urban cosmography’, a concept inspired by early modern artisans' attempts to chart the contours of the world, both known and unknown. Seen from this perspective, historical graphics such as maps, posters, and birds-eye views document a city's position within a continually evolving universal order. This paper will review graphics drawn from the history of one city in particular: Baltimore, Maryland. Like other cities on the eastern seaboard of the US, Baltimore has been represented by diverse visual arts for more than two centuries. With the advent of digital and social media, Baltimore's development will depend even more upon the city's local and global interrelationships. ‘Urban cosmography’ is, therefore, a useful conceptual prism through which one may perceive the link between the city's historical legacy and contemporary urban challenges. One consequence is that visual tropes for traditional urban polarities – ‘growth’ versus ‘decay’, for instance – may be superseded by new symbols that incorporate both.     

基于整体保护的城市大遗址区可持续发展研究--以西安大明宫遗址为例

位于城市中心的大遗址不仅面临遗产保护的重任,同时面对遗址区社会、经济各项事业发展的要求,传统“单点保护”模式在快速城市化的冲击下已不能适应遗址“真实性、完整性”保护的要求,西安市在大明宫遗址保护中探索“整体保护、积极利用”的大遗址保护模式,将大遗址保护与城市整体发展相结合,为城市中心型大遗址保护提供了新经验。     

Refashioning urban space in postwar Toronto: the Wood-Wellesley redevelopment area, 1952–1957

This paper considers the creation and the subsequent meaning of ‘redevelopment areas’ in Toronto in the 1950s. The city passed a bylaw in 1952 that defined blighted areas as suitable for redevelopment. One of these areas was the downtown district that runs between Wood and Wellesley streets. The history of the Wood-Wellesley redevelopment area between 1952 and 1957 was important in several ways: it built on but differed from similar activity in the USA; it discursively reflected the needs of the city to refashion itself as a modern landscape; it provided the city with the tools to turn planning ideas into action; and it gave developers the forum by which they could push for specific areas of the city to be opened up for investment. Politically calculated and heavily contested visions of urban space, redevelopment areas such as Wood-Wellesley were used by the state and developers to physically reconstruct Toronto’s downtown area for private capital, to create a new modernist landscape, and to reproduce new and to reinforce existing social inequalities.     

City profile: Medellin

After being known as the ‘murder capital of the world’ in the 1990s, Medellin has pioneered innovative forms of city planning and management and was acclaimed the most innovative city in the world by the Urban Land Institute (ULI) in 2013. Hosting the World Urban Forum in 2014 allowed it to showcase its approach, key elements of which have been: creation of innovative transport infrastructure linking poorer peripheral districts to the city centre; culture-led regeneration; strong support of local development from the local business sector; and a successful municipally-owned utilities company. However, the city is spreading outwards without services and employment being provided; new low-income developments are replicating high-rise models which failed worldwide; there is limited intervention in the existing informal areas, many being in highly vulnerable locations where the level of risk is likely to increase with climate change; development has little regard for topography, ecological and environmental considerations; investment in accessible and good quality public space is restricted to some areas; the quality of the public realm does not always support health and wellbeing of the ageing population. This paper explores the institutional and socio-economic context in which Medellín has achieved the internationally recognized status of an ‘innovative city’. It questions to what extent social equity, environmental sustainability and citizen empowerment have been promoted as per the ULI claims when it conferred the prize. The paper queries the extent to which ‘urban innovation’ is happening in Medellín, which has considerable implications given its recently found role as a ‘model’ city in Latin America and beyond.     

Towards democratic planning? Negotiating change in St Kilda,Melbourne

Are planners ‘dealmakers’ caught up in selling urban areas to the highest bidder, or are they negotiators concerned to maintain democratic planning and social diversity in areas that are subject to gentrification? This paper explores this question through the example of two sites in St Kilda, Melbourne. The sites highlight planning strategies used at the local government level by planners who are attempting to negotiate change and to maintain the social and cultural diversity of the area. The first example illustrates the processes of ‘democratic planning’ where planners question what is ‘legitimate’ and draw on discourses of local need. The second example illustrates the problems of co‐opting local culture within a process of democratic planning that is based on community consultation. Together, the examples illustrate the need for tighter local government policies, including stricter policies about the use of developer contributions, and a closer and more critical focus on the term ‘community consultation’, if democratic planning is to be achieved.     

Resilient urban forms: A macro-scale analysis

Cities need to build on their resilience to cope with a broad range of natural and manmade hazards that threaten their competitiveness, livability, and functionality. Recognizing this need, the resilience concept is increasingly used as an organizing principle to guide research design and facilitate a more informed decision-making process. However, despite the abundance of studies on urban resilience, research on the link between urban form and resilience is limited and fragmented. This study sheds more light on this issue by reviewing and synthesizing theoretical and empirical evidence on how physical structure of cities can facilitate or hinder urban resilience. Acknowledging that each city is located within a nested hierarchy of scales that is characterized by cross-scale dynamics, only the macro-level aspects and elements of urban form are analyzed in this paper. These are namely ‘scale hierarchy’, ‘city size’, ‘development type’, ‘degree of clustering’, and ‘landscape/habitat connectivity’. Key criteria and indicators for analyzing resilience of each element/aspect are specified and used to discuss how macro-scale urban form is related to various resilience properties such as robustness, redundancy, resourcefulness, modularity, flexibility, adaptability, and efficiency. Findings indicate that urban form has major implications for social, ecological, and economic functionality of cities and can play a key role in enhancing their resilience and sustainability.     

Negotiating an Asiatown in Berlin: Ethnic diversity in urban planning

Cities are increasingly affected by migration which raises new questions for urban development and planning. In the paper at hand, this issue is addressed from two perspectives: First, we stress the high social, representative as well as economic potential of ethnic economies and the emerging neighborhoods, showing that they serve migrant communities as well as urban development. Second, we bring in perspectives from the ‘planning for diversity’ and ‘multicultural planning’ discourses into the German debate. This paper takes the planning conflict on the development of the Dong Xuan Center (DXC), Germany's largest Vietnamese-run trade center, into an Asiatown as empirical basis. It examines legal implications for the German context and therewith contributes to the ‘planning for diversity’ discourse from a non-multicultural setting.